A novel method for artery detection in laparoscopic surgery.

BACKGROUND: One of the most important difficulties in laparoscopic surgery is intraoperative blood vessel detection. An accidental injury to a blood vessel may cause serious complications and could result in changing from a laparoscopic procedure to open surgery. Moreover, differentiating arteries from veins is necessary in all surgical cases. In this study we evaluate a new image-processing method for artery detection that would be useful during laparoscopic and endoscopic procedures. It is possible to install the program on any ordinary laparoscopy set and it displays the artery's region on the monitor. METHODS: This method uses the artery's pulse to detect an artery and distinguish it from veins. By subtracting the systolic and diastolic images, the change regions are detected and shown on a monitor. The performance of this method in detecting arteries in simulation and in real laparoscopic surgery is evaluated. Artery detection in different pulse rates, different artery depths, and different blood pressures is tested via the simulation phase. It is also tested in two laparoscopic surgeries, one on a kidney and one on a stomach. RESULTS: In simulation phase the method can correctly detect all arteries that are not too deep and can move superficial tissues with zero false-negative and false-positive rates. In real laparoscopy, the false-positive rate was 8% and the false-negative rate was 5%. CONCLUSION: This method is a noninvasive, reliable, and cost-effective technique to detect artery regions, even if some of them are covered with fat or other tissues, while suppressing veins and other tissues.

Three-dimensional combination of transrectal and transperineal biopsies for efficient detection of stage T1c prostate cancer.

BACKGROUND: Although an increasing number of men present with stage T1c prostate cancer, the optimal biopsy strategy for detecting stage T1c disease still remains to be defined. The aim of this study was to explore an efficient first-time biopsy scheme for detecting stage T1c and T2 prostate cancer. METHODS: A transrectal ultrasound-guided systematic three-dimensional 26-core (3D26) biopsy comprising 12 transrectal and 14 transperineal sampling sites was performed in 321 men with median prostate-specific antigen (PSA) level of 6.0 ng/ml in the first-time biopsy setting. By analyzing site-specific cancer detection rates, we determined the best combination of transperineal and transrectal sampling sites. RESULTS: Prostate cancer was detected in 109 of the 321 men (34%) with a major complication rate of 0.6%. 3D26 biopsy significantly improved cancer detectability by 60% relative to the conventional transrectal sextant (TR6) biopsy. Improvement was significant in 263 men with normal digital rectal examination (DRE) (85%, P = 0.0004) but not in 58 men with abnormal DRE (22%, P = 0.18). The mean Gleason score of the 41 cancers without a positive core within the TR6 sites was marginally lower than that of 68 cancers with a positive core within the TR6 sites (P = 0.04). Recursive partitioning revealed that a three-dimensional 14-core (transrectal 8-core plus transperineal 6-core) and a three-dimensional 8-core (transrectal 4-core plus transperineal 4-core) biopsies could detect more than 95% of stage T1c and T2 cancers with a minimum number of cores, respectively. CONCLUSION: We propose a three-dimensional 14-core and a three-dimensional 8-core biopsy as efficient first-time biopsy schemes to detect stage T1c and T2 prostate cancer, respectively.